Write the conversation response. 
[+] What are some sources of wastewater?
[+] Activities producing industrial wastewater include:  Other related activities or events:  Wastewater can be diluted or mixed with other types of water through the following mechanisms: The composition of wastewater varies widely.
[+] What are some examples of the types of things that can be in wastewater?
[+] This is a partial list of pollutants that may be contained in wastewater: If the wastewater contains human feces, as is the case for sewage, then it may also contain pathogens of one of the four types: It can also contain non-pathogenic bacteria and animals such as insects, arthropods and small fish. Since all natural waterways contain bacteria and nutrients, almost any waste compounds introduced into such waterways will initiate biochemical reactions such as detailed above.
[+] How is the cleanliness of the waterways affected by the introduction of wastewater?
[+] Those biochemical reactions create what is measured in the laboratory as the biochemical oxygen demand (BOD).
[+] What else is measured in the laboratory?
[+] Such chemicals are also liable to be broken down using strong oxidizing agents and these chemical reactions create what is measured in the laboratory as the chemical oxygen demand (COD).
[+] What do the COD and BOD measurements mean?
[+] Both the BOD and COD tests are a measure of the relative oxygen-depletion effect of a waste contaminant.
[+] Are the measurements used in a scientific way?
[+] 
Both have been widely adopted as a measure of pollution effect.